A wide variety of electronic devices communicate within modern vehicles. These communications often take place over a vehicle bus that operates to route signals between electronic modules within the vehicle system. However, communication with a module from outside of the vehicle system is difficult and has been undesirably limited. For example, the ability to affect vehicle bus operation has been constrained to direct instructions without the ability to route the signal based on the signal contents. To solve this limitation, smart cable protocol converters that are able to convert the format, or protocol, of the signal, have been used, but these converters merely translate a signal from one format into another format and do not actively determine a destination of the signal.
For example, use of a TTY (Text Telephony or Teletypewriter) devices via a cell phone has historically required an audio cable to allow modulated tones (between 1400 Hz and 1800 Hz) to pass through a voice channel after the call has been established. While such an approach is feasible for a cell phone user, telephony devices that are embedded in a vehicle, or otherwise inaccessible to a user, are unable to take advantage of such arrangements.
The present invention advances the state of the art in vehicle bus communications.